Device for adjusting the position of the operating lever of a hydraulic actuator

ABSTRACT

A device for adjusting the position of the brake lever of a motorcycle comprises a bracket ( 5 ) connectable to a handlebar ( 4 ), a brake lever ( 2 ) extending in an essentially longitudinal direction (X-X), pivotally mounted on the bracket ( 5 ) and intended to be moved towards or away from a hydraulic actuator ( 3 ), and an adjustment lever ( 9 ) pivotally mounted on the bracket ( 5 ) and functionally connected to the brake lever ( 2 ) in order to operate the hydraulic actuator ( 3 ) when the brake lever ( 2 ) moves towards the hydraulic actuator ( 3 ). The device ( 1 ) possesses means ( 15 ) for adjusting the position of the brake lever ( 2 ) with respect to the adjustment lever ( 9 ), these means comprising a pin ( 16 ) extending in the longitudinal direction (X-X) in a continuation of the brake lever ( 2 ), which pin is engaged in such a way that it can be adjusted axially with respect to the brake lever ( 2 ) and is engaged in abutment with the adjustment lever ( 9 ), so that a movement in the longitudinal direction (X-X) of the pin ( 16 ) with respect to the brake lever ( 2 ) corresponds to a change in the position of the brake lever ( 2 ) with respect to the adjustment lever ( 9 ).

This application is the U.S. national phase of international applicationPCT/EP01/03314 filed 23 Mar. 2001, which designated the US. US NationalPhase of PCT/EP01/03314.

The present invention relates to a device for adjusting the position ofthe operating lever of a hydraulic actuator, especially the pump of thebrake system or of the hydraulic clutch of a motorcycle.

With the sole purpose of simplifying the explanation of the presentinvention, the remainder of the description will refer to ahand-controlled lever fitted to the handlebar of a motorcycle foroperating the pump of the brake system, hereinafter termed the brakelever.

As is well known, in motorcycles, the brake lever is positioned at theright-hand end of the handlebar, close to the steering handgrip on whichthe throttle control is fitted.

It is also well known that the position of the brake lever, or to bemore precise the distance between the brake lever and the handlebarhandgrip, is very often not quite appropriate for the real needs of manyusers, owing to the anthropometric differences of each person. There istherefore a widely felt need to be able to provide a device foradjusting the distance between the brake lever and the handlebarhandgrip in a precise and rapid manner.

This need is especially familiar to racing motorcyclists, for whom theabsolute precision and reduced fatigue of operation of the brake leverduring trials and/or racing is essential if the maximum performance isto be obtained during a race.

In order to meet this need it has been proposed that use be made ofdevices capable of adjusting the position of the brake lever withrespect to the hydraulic actuator and hence also with respect to thehandlebar handgrip of the motorcycle.

Known adjustment devices comprise a main lever and an adjustment leverconnected to it to operate the pump of the brake system as the mainlever is brought towards the handlebar handgrip. The main lever and theadjustment lever are connected to each other by a threaded pin which canbe rotated to adjust the position of the main lever with respect to thatof the adjustment lever and hence the distance between the handlebarhandgrip and the main lever on which the user acts manually in order tobrake.

It should be pointed out that the abovementioned adjustment devices havethe drawback of not allowing the distance between the main lever and thehandlebar handgrip to be adjusted unless the motorcycle is stationary.This is because, in the abovementioned adjustment devices, the threadedpin that allows the position of the main lever to be adjustedsubstantially lies in the continuation of the axis of the brake pumppiston, i.e. along a direction more or less perpendicular to thelongitudinal axis of the main lever. In practice, therefore, it isimpossible for the user to operate the adjustment device without takinghis hands off the handlebar handgrip.

In this connection it may be observed that for a normal user it isacceptable, though inconvenient, to stop in order to adjust the positionof the brake lever. However, for a racing motorcyclist involved in acompetition, the idea of stopping in order to carry out an adjustment isquite out of the question, and it is not even possible to take the handoff the handlebar handgrip to which the throttle control is fitted.

Accordingly, the adjustment device must be easy to operate while thevehicle is moving without compromising the safety of the rider. It isworth pointing out that the need to vary the position of the brake leverwhile the vehicle is in motion arises in other situations than racing,for example during a long motorway journey.

The use of a remote-operated control system comprising a flexible cablecapable of transmitting a twisting moment as a means of turning the pinhas been proposed. However, the flexible cable has to negotiate an atleast 90° bend of short radius close to the point of connection to thethreaded pin, which introduces friction, irregularity and imprecision inthe operation of the adjustment device.

The need for the wire to make the abovementioned bend could be obviatedby introducing a bevel gear transmission between the end of the threadedpin that is to be turned, and the end of the flexible connecting cable.This would greatly increase the complexity of construction of theadjustment device, besides increasing the size and cost of manufacture,so militating against the use of this transmission.

The problem addressed by the present invention is that of devising andproviding a device for adjusting the position of the operating lever ofa hydraulic actuator, such as a motorcycle brake lever, the structuraland functional characteristics of this device being such as to fulfilthe above requirements and, at the same time, to overcome the drawbackscited with reference to the prior art.

This problem is solved by a device for adjusting the position of theoperating lever of a hydraulic actuator in accordance with claim 1.

Other characteristics and the advantages of the adjustment deviceaccording to the invention will become clear in the course of thedescription given below of certain preferred embodiments thereof. Theseexamples are provided by way of non-restrictive guidance and refer tothe accompanying figures, in which:

FIG. 1 is a plan view of an adjustment device according to theinvention;

FIG. 2 is a plan view with parts in section of the adjustment deviceseen in FIG. 1;

FIG. 3 is a sectional view through a detail of the adjustment devicetaken on 111-III as marked in FIG. 1;

FIG. 4 is a plan view of a detail of the device seen in FIG. 1,

FIG. 5 is a perspective view of the detail seen in FIG. 4,

FIG. 6 is a plan view of another detail of the device seen in FIG. 1,and

FIG. 7 is a plan view with parts in section of the adjustment deviceseen in FIG. 1 in accordance with a different use configuration.

Referring to the accompanying drawings, the number 1 is a generalindication for a device for adjusting the position of the operatinglever 2 of a hydraulic actuator 3 such as the brake pump of the brakesystem or of the hydraulic clutch of a motorcycle. In the exampleconsidered here, the abovementioned operating lever is thehand-controlled lever mounted on the handlebar 4 (only partly indicatedin broken lines in the figures) of a motorcycle. By acting on this leverit is possible to operate the brake pump 3 of the brake system. In theremainder of this text the abovementioned lever will be referred to asbrake lever 2. As is well known, the brake lever 2 is positioned at theright-hand end of the motorcycle handlebar, close to the handgrip towhich the throttle control is fitted.

The adjustment device 1 comprises a bracket 5 with means for mounting itfirmly on a supporting structure which, in the example, is the handlebar4 of the motorcycle.

The brake lever 2 comprises an end block 2 a from which a slender part 2b extends in an essentially longitudinal direction X-X. The slender partis intended to be grasped by a user of the motorcycle using the fingersof the hand, while the palm bears against the corresponding handlebarhandgrip. The slender part 2 b of the brake lever 2 is shaped to acurved line so as to be ergonomical and make it easier to grip. In thisdescription the expression “longitudinal direction X-X” is used to referto that direction defined by the straight line passing through the endblock 2 a of the brake lever 2 and interpolating the line of the slenderpart 2 b (FIG. 1).

In the example seen in the figures, the end block 2 a and the slenderpart 2 b of the brake lever 2 are two separate parts joined together bya connecting screw. The brake lever 2 may have also been made in onepiece.

The end block 2 a of the brake lever 2 is pivotally mounted on thebracket 5 by means of a pin 6, thus being able to move angularly towardsand away from the corresponding handgrip of the handlebar 4. The pin 6extends in a direction Z-Z that substantially coincides with the normalto the plane passing through both the brake lever 2 and the handlebar 4(i.e. normal to the plane of the drawing in FIGS. 1 and 2).

The brake pump 3 is integral with the bracket 5 and, in the example, ispositioned so that the piston which it contains is able to move in atransverse direction Y-Y running from the handle 4 towards the brakelever 2, between an end-of-travel rest position (FIG. 2), to which thepiston 7 is urged by an opposing spring 8, and an advanced workingposition to which the piston 7 moves when the brake pump 3 is pushedagainst the opposing spring 8 and against the pressure of the brakefluid contained inside the body of the brake pump 3. In particular, whenmoving from the end-of-travel rest position to the advanced position,the piston 7 moves towards the handlebar 4 along the transversedirection Y-Y.

Connected to the piston 7 is a control rod 10 extending roughly in thetransverse direction Y-Y and projecting from the body of the brake pump3 from the end nearest the brake lever 2. When the control rod 10 isdepressed with a defined axial force, the brake pump 3 is operated,meaning that the piston 7 advances from the end-of-travel rest positionto an advanced position.

In a purely conventional way, the brake pump 3 has hydraulic fluid inletand outlet apertures. The end-of-travel rest position of the piston 7 isadjusted so that in this position the piston 7 does not close thehydraulic fluid inlet aperture of the brake pump 3.

It will be clear from the above that when the brake lever 2 moves eithertowards or away from the handlebar 4 handgrip, the brake lever 2 issimultaneously moving towards or away from, respectively, the brake pump3.

The adjustment device 1 also includes an adjustment lever 9 that ispivotally mounted on the bracket 5 and is functionally connected to thebrake lever 2 so as to act on the control rod 10 and operate the brakepump 3 when the brake lever 2 is pulled towards the said brake pump.

The adjustment lever 9 is preferably in line with the brake lever 2 andis pivotally mounted on the bracket 5 by the same pin 6, so that itmoves together with the brake lever 2 towards and away from the brakepump 3 and hence towards and away from the handlebar 4 handgrip.

The rear portion of the adjustment lever 9 includes a bearing surface 13by way of an end stop for the rotation of the adjustment lever 9 aboutthe pin 6 away from the brake pump 3 (anticlockwise direction withreference to FIGS. 1 and 2): when the adjustment lever 9 rotates awayfrom the brake pump 3, the bearing surface 13 interferes with thebracket 5, abutting against it in an end-of-travel position.

The action of the opposing spring 8 on the piston 7 of the brake pump 3causes the control rod 10 to act on the adjustment lever 9 in such adirection that it tends to hold its bearing surface 13 against thebracket 5 with a predetermined elastic load.

A threaded through hole 11 is preferably formed in the adjustment lever9 with the threaded shank of an adjustment screw 12 screwed into it. Theadjustment screw 12 has a head 12 a projecting from the adjustment lever9 on which the end of the control rod 10 acts. Consequently the effectof screwing or unscrewing the adjustment screw 12 into or out of theadjustment lever 9, thereby varying the distance between the head 12 aand the adjustment lever 9, is to adjust the position taken up by thecontrol rod 10 and hence to adjust the abovementioned end-of-travel restposition of the piston 7 inside the brake pump 3.

The end of the control rod 10 that acts against the adjustment screw 12is preferably rounded, while the head 12 a of the adjustment screw 12 isgiven a flared hemispherical recess to take the abovementioned roundedend of the control rod 10.

Alternatively, the adjustment means used to adjust the relative positionof the adjustment lever 9 with respect to the brake pump 3, i.e. therest end-of-travel of the piston 7, may take the form of other,functionally equivalent elements, such as a grub screw.

The rotational end of travel of the adjustment lever 9 and of the brakelever 2 as they move towards (clockwise direction with reference toFIGS. 1 and 2) the brake pump 3 is determined by the furthest possibleadvanced working position of the piston 7 before the latter touches thebottom of the body of the brake pump 3 or before the turns of theopposing spring 8 become fully closed.

The adjustment device 1 is also provided with means 15 for adjusting theposition of the brake lever 2 with respect to the adjustment lever 9,that is to say adjustment of the distance between the slender part 2 bof the brake lever 2 and the corresponding handlebar 4 handgrip.

In the example, the abovementioned means 15 for adjusting the positionof the brake lever 2 with respect to the adjustment lever 9 comprise apin 16 oriented approximately along the said longitudinal direction X-X.The pin 16 is engaged with the brake lever 2 in such a way that it canbe adjusted axially along the abovementioned longitudinal direction X-Xand, at the same time, is engaged in abutment with the adjustment lever9, so that a movement in the longitudinal direction X-X of the pin 16with respect to the brake lever 2 corresponds to a change in theposition of the brake lever 2 with respect to the adjustment lever 9.

In a preferred embodiment, the engagement whereby the pin 16 can beadjusted axially along the longitudinal direction X-X relative to thebrake lever 2 is provided by the fact that the pin 16 has an externalthread screwed into a threaded through hole 18 running through acentring support 14. This centring support 14 extends axially in theabovementioned vertical direction Z-Z and is pivotally mounted in theend block 2 a of the brake lever 2 so as to be able to rotate about itsown axis. Consequently it is possible, by rotating the pin 16 withrespect to the centring support 14, to alter the relative position ofthe pin 16 with respect to the brake lever 2 in the longitudinaldirection X-X.

The end 20 of the threaded pin 16 projecting from the abovementionedthrough hole 18 abuts against the adjustment lever 9. To this end theadjustment device 1 comprises elastic means 19 acting on the end block 2a of the brake lever 2 and on the adjustment lever 9 in order tomaintain contact, with a defined elastic load, between the end 20 of thethreaded pin 16 and the adjustment lever 9. In the example the elasticmeans 19 take the form of two helical springs 19, each acting betweenopposing end portions of the brake lever 2 and of the adjustment lever9, such as to cause the brake lever 2 to rotate about the pin 6 andtowards the brake pump 3 (clockwise direction with reference to FIGS. 1and 2), thereby taking up any slack and ensuring that the abovementionedlevers do not chatter against each other when subject to vibrations andthe like.

The end 20 of the threaded pin 16 is preferably rounded and in abutmentwith a corresponding flared hemispherical recess 21 formed in theadjustment lever 9.

The abovementioned means 15 for adjusting the position of the brakelever 2 with respect to the adjustment lever 9, in other words thethreaded pin 16, are advantageously accessible and can therefore becontrolled from outside of the adjustment device 1, more specificallyfrom the outer region of the adjustment device, where the inner regionof the adjustment device 1 is taken to be that defined between theslender part 2 b of the brake lever 2 and the brake pump 3, i.e. thatfacing the handlebar 4 handgrip.

The pin 16 preferably extends in the longitudinal direction X-X in anapproximate continuation of the brake lever 2, or more precisely of theslender part 2 b of that lever.

Connected to the pin 16 is a control member, e.g. a knurled nut 22 orthe like, that can easily be turned even with just one digit of thehand, such as the thumb. The knurled nut 22 preferably engages with anend portion of the pin 16 projecting from the end block part 2 a of thebrake lever 2.

If it is wished to rotate the pin 16 using the left hand rather than theright hand, the knurled nut 22 can be replaced with remote means ofoperation 23 (shown in FIG. 7). In the example considered, the remotemeans of operation 23 comprise a flexible cable 24 capable oftransmitting a twisting moment and connected at one end to theaforementioned end portion of the pin 16 projecting from the end blockpart 2 a of the brake lever 2 and, at the other end, to a control member30 located in the vicinity of the left-hand handgrip on the left side ofthe motorcycle handlebar.

It is worth observing that the adjustment device 1 according to theinvention does not require the presence of a bevel gear transmissionbetween the end of the threaded pin 16 (which requires rotating) and theend of the flexible cable 24, and this without requiring the cable tonegotiate any sharp, short-radius bend.

The adjustment device 1 according to the invention permits a quick andeasy interchange between a control member such as the knurled nut 22 andremote means of operation.

In consideration of the above, the adjustment device 1 according to theinvention is particularly suitable for use on motorcycles used incompetitive sports.

To enable greater sensitivity in the adjustment of the distance of thebrake lever 2 from the brake pump 3 and hence from the handlebar 4handgrip, the adjustment device 1 may advantageously include means 25for indexed rotary advancing of the threaded pin 16 with respect to thebrake lever 2.

With particular reference to FIG. 3, the means 25 for indexed rotaryadvancing comprise a ball 26 in a cylindrical hole formed in thecentring support 14 transversely with respect to the threaded hole 18and in communication with the latter. A helical spring 27 acts on theball 26 and, as the threaded pin 16 rotates, pushes the ball 26 in turninto one indentation, or formed location, 28 of the plurality of axialindentations 28 recessed into the outer surface of the threaded pin 16.

In the operation of the adjustment device 1, it is found that rotationin either direction of the threaded pin 16 with respect to the end block2 a of the brake lever 2 produces a corresponding rotation of the brakelever 2 with respect to the adjustment lever 9 about the common pin 6and consequently a change in the distance between the slender part 2 bof the brake lever 2 and the corresponding handlebar 4 handgrip.

As mentioned, the threaded pin 16 can be rotated by means of a controlnut connected to it directly or via a remote means of operation.

As will be appreciated from the above description, the adjustment deviceaccording to the invention fulfils the abovementioned requirements andat the same time overcomes the disadvantages referred to in theintroductory part of the description.

Other advantages of the adjustment device according to the invention areto be found in:

-   -   the adjustment of the rest position of the pump piston        independently of the position of the main lever;    -   the option of adopting a highly precise “screw” system of        adjustment;    -   the simplicity of construction and resulting low cost of        manufacture.

Clearly, in order to fulfil particular and specific requirements, aperson skilled in the art will be able to make numerous modificationsand alterations to the adjustment device according to the inventiondescribed above, all however falling within the scope of protection ofthe invention as defined in the following claims.

For example, in contrast to what is outlined above, the pin 16 may beengaged with the adjustment lever in such a way that it can be adjustedaxially along the longitudinal direction X-X and at the same time be inabutment with the brake lever.

In contrast to what is outlined above, if, for manufacturing reasons,the hydraulic actuator is positioned such that its piston moves in thelongitudinal direction X-X defined above or in some other directiondifferent from direction Y-Y previously considered, the adjustment levercan simply have a part shaped like an L or in some other equivalent wayin order to make the hydraulic actuator efficiently operable.

1. Device for adjusting the position of the operating lever of ahydraulic actuator for a motorcycle, comprising: a bracket connectableto a supporting structure, a hydraulic actuator connected to thebracket; a main lever extending in an essentially longitudinaldirection, pivotally mounted on the bracket and intended to be movedtowards or away from the hydraulic actuator, the main lever having anouter end portion, and an elongated inner handgrip portion extendinginwardly in said longitudinal direction and being movable toward andaway from the hydraulic actuator; an adjustment lever pivotally mountedon the bracket and functionally connected to the main lever in order tooperate the hydraulic actuator when the main lever moves towards thehydraulic actuator, wherein: said device also comprises means foradjusting the position of the main lever with respect to the adjustmentlever, the adjusting means being accessible from the outer end portionof the main lever and comprising a pin oriented along said longitudinaldirection and being disposed on the outer end of the outer end portionof the main lever remote from the inner handgrip portion thereof, thepin being constructed and positioned for connection to means of remoteoperation capable of transmitting a twisting moment avoiding shortradius bend in the means of remote operation, wherein the pin is engagedin such a way that the pin can be adjusted axially along saidlongitudinal direction on the outer end portion of the main lever, andwherein the pin is engaged in abutment with the adjustment lever, sothat a movement in said longitudinal direction of the pin with respectto the main lever corresponds to a change in the position of the mainlever with respect to the adjustment lever, the pin comprising athreaded portion, and a centring support pivotally mounted on the mainlever, the pin being in threaded engagement with the centring support,so that, by screwing the pin into or out of the centring support, theposition of the pin can be adjusted along said longitudinal direction,wherein elastic means acting between opposing end portions of the mainlever and of the adjustment lever causes the main lever to rotatetowards the hydraulic actuator and maintain contact, with a definedelastic load between the pin and the adjustment lever.
 2. The deviceaccording to claim 1, comprising means for indexed rotary advancing ofthe threaded pin with respect to the main lever.
 3. The device accordingto claim 2, in which the means for indexed rotary advancing comprise aball in a cylindrical seat formed in the centering support, on whichball there acts a spring which, as the pin rotates, pushes the ball inturn into one axial indentation of a plurality of axial indentationsrecessed into the outer surface of the threaded portion of the pin. 4.The device according to claim 1, in which the pin lies in a continuationof the longitudinal direction of the main lever.
 5. The device accordingto claim 1, in which the main lever and the adjustment lever are bothpivotally mounted on the bracket on the same axis.
 6. The deviceaccording to claim 1, in which the adjustment lever comprises a bearingsurface designed to abut against a surface of the bracket so as todefine an end of travel for the rotation of the adjustment lever andmain lever away from the hydraulic actuator.
 7. The device according toclaim 1, in which the hydraulic actuator can be operated by means of acontrol rod and in which the adjustment device comprises adjustmentmeans for adjusting the relative position of the adjustment lever withrespect to the control rod.
 8. The device according to claim 1, in whicha control member is connected to the pin.
 9. The device according toclaim 1, in which means of remote operation are connected to the pin andextend outwardly from the outer end portion in the longitudinaldirection of the main lever.
 10. The device according to claim 1 whereinone end of the pin is in abutment in a flared hemispherical recessformed in the adjustment lever.
 11. the device according to claim 1,further comprising means of remote operation comprising a flexible cablecapable of transmitting a twisting movement, one end of the flexiblecable being connected to the pin and the other end being connected to acontrol member, said flexible cable extending outwardly from the outerend portion in the longitudinal direction of the main lever.